Controlling access to a network server using an authentication ticket

ABSTRACT

A system determines whether to grant a user access to a network server. Prior to granting access to the network server, the network server authenticates the user by sending an authentication request to an authentication server. The authentication server determines whether the user was already authenticated by the authentication server. If the user is authenticated by the authentication server, then the network server is notified that the user is authenticated through the use of an authentication ticket, and the network server grants the network server user access. If the user is not authenticated by the authentication server, then login information is retrieved from the user and compared to authentication information maintained by the authentication server. If the retrieved login information matches the authentication information, then the network server is notified that the user is authenticated by using the authentication ticket.

TECHNICAL FIELD

This invention relates to network access systems. More particularly, theinvention relates to the control of access to a network by a userthrough an authentication server that generates an authentication ticketindicating whether the user has been authenticated.

BACKGROUND OF THE INVENTION

The recent growth in popularity of the Internet has significantlyincreased the number of Internet users and the number of Internet sites(also referred to as “web sites”). Web sites may provide various typesof information to users, offer products or services for sale, andprovide games and other forms of entertainment. Many web sites requireusers to “register” by providing information about themselves before theweb server grants access to the site. This registration information mayinclude the user's name, account number, address, telephone number,email address, computer platform, age, gender, or hobbies. Theregistration information collected by the web site may be necessary tocomplete transactions (such as commercial or financial transactions).Additionally, information can be collected which allows the web siteoperator to learn about the visitors to the site to better target itsfuture marketing activities or adjust the information provided on theweb site. The collected information may also be used to allow the website to contact the user directly (e.g., via email) in the future toannounce, for example, special promotions, new products, or new featuresof the web site.

When registering with a web site for the first time, the web sitetypically requests that the user select a login ID and an associatedpassword. The login ID allows the web site to identify the user andretrieve the user's information during subsequent user visits to the website. Generally, the login ID must be unique to the web site such thatno two users have the same login ID. The password associated with thelogin ID allows the web site to authenticate the user during subsequentvisits to the web site. The password also prevents others (who do notknow the password) from accessing the web site using the user's loginID. This password protection is particularly important if the web sitestores private or confidential information about the user, such asfinancial information or medial records.

If a user visits several different web sites, each web site may requireentry of similar registration information about the user, such as theuser's name, mailing address, and email address. This repeated entry ofidentical data is tedious when visiting multiple web sites in a shortperiod of time. Many web sites require the user to register beforeaccessing any information provided on the web site. Thus, the user mustenter the requested registration information before they can determinewhether the site contains any information of interest.

After registering with multiple web sites, the user must remember thespecific login ID and password used with each web site or other Internetservice. Without the correct login ID and password, the user mustre-enter the registration information. A particular user is likely tohave different login IDs and associated passwords on different websites. For example, a user named Bob Smith may select “smith” as hislogin ID for a particular site. If the site already has a user with alogin ID of “smith” or requires a login ID of at least six characters,then the user must select a different login ID. After registering atnumerous web sites, Bob Smith may have a collection of different loginIDs, such as: smith, smith1, bsmith, smithb, bobsmith, bob_smith, andsmithbob. Further, different passwords may be associated with differentlogin IDs due to differing password requirements of the different websites (e.g., password length requirements or a requirement that eachpassword include at least one numeric character). Thus, Bob Smith mustmaintain a list of web sites, login IDs, and associated passwords forall sites that he visits regularly.

SUMMARY OF THE INVENTION

The invention provides a mechanism for controlling access to a networkserver (such as a web server) through the use of an authenticationticket. A web user can maintain a single login ID (and associatedpassword) that provides access to multiple web servers or services. Oncethe user has logged into an authentication server, it is not necessaryto re-enter the login ID or user information when accessing otheraffiliated web servers. The single login ID has an associated userprofile that contains the registration information typically requestedby web servers during a user registration process. The authenticationserver authenticates each login ID using the associated password andgenerates an authentication ticket indicating whether the user isauthenticated (i.e., whether the user should be granted access to theweb server). The individual web servers are not required to authenticatethe individual users. Further, to protect the user's password, theindividual web servers do not receive the user's password. Instead, theindividual web servers receive an authentication ticket indicatingwhether the user was authenticated by the authentication server and howlong since the user was last authenticated. The authentication ticketincludes two time stamps: one indicating the last time the user's loginID and password were physically typed by the user and a second timestamp indicating the last time the user's login information wasrefreshed by the authentication server. This “refresh” of the user'slogin information may be performed silently or by having the user typethe login information.

An implementation of the invention receives a request from a networkserver to authenticate a user who is seeking access to the networkserver. The process determines whether the user was alreadyauthenticated by the authentication server. If the user was alreadyauthenticated, then the network server is notified that the user isauthenticated through the use of an authentication ticket. If the userwas not already authenticated by the authentication server, then logininformation is retrieved from the user and compared to authenticationinformation maintained by the authentication server. The network serveris notified (through the use of an authentication ticket) that the useris authenticated if the retrieved login information matches theauthentication information.

Other aspects of the invention provide for an authentication ticket thatdoes not contain any reference to the user's login information.

In accordance with another aspect of the invention, the authenticationticket includes a first time stamp indicating the last time the user'slogin information was refreshed, and a second time stamp indicating thelast time the user physically entered their login information.

In one embodiment of the invention, the network server is a web servercoupled to the Internet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary network environment in which the presentinvention is utilized.

FIG. 2 is a block diagram showing pertinent components of a computer inaccordance with the invention.

FIGS. 3 and 4 illustrate the interaction between the client computersystem, a particular affiliate server and the authentication server whena user of the client computer system seeks access to the affiliateserver.

FIGS. 5 and 6 illustrate the interaction between the client computersystem, a particular affiliate server and the authentication server in adifferent situation.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary network environment in which the presentinvention is utilized. A client computer system 100 is coupled to anetwork 102. In this example, network 102 is the Internet (or theWorld-Wide Web). However, the teachings of the present invention can beapplied to any data communication network. Multiple affiliate servers104, 106, and 108 are coupled to network 102; thereby allowing clientcomputer system 100 to access web servers 104, 106, and 108 via thenetwork. Affiliate servers 104, 106, and 108 are also referred to as“web servers” and “network servers”. An authentication server 110 isalso coupled to network 102, allowing communication between theauthentication server and client computer system 100 and web servers104, 106, and 108. Although referred to as an “authentication server”,authentication server 110 is also a web server capable of interactingwith web browsers and other web servers. In this example, data iscommunicated between the authentication server, client computer system,and web servers using the hypertext transfer protocol (http), a protocolcommonly used on the Internet to exchange information.

An authentication database 112 is coupled to authentication server 110.The authentication database 112 contains information necessary toauthenticate users and also identifies which elements of the userprofile information should be provided to a particular affiliate serverwhen the user accesses the affiliate server. Although the authenticationdatabase 112 is shown separately from the authentication server 110, inother embodiments of the invention, the authentication database iscontained within the authentication server.

The authentication process, as described below, authenticates a user ofclient computer 100 seeking access to an affiliate server 104, 106, or108. The authentication server 110 authenticates the user of clientcomputer 100 by requesting authenticating information, such as theuser's login ID and password. If the user is successfully authenticated,then authentication server 110 generates an authentication ticket andcommunicates the ticket to the appropriate affiliate server. Theauthentication ticket indicates that the user is authenticated.Additional details regarding the authentication ticket are providedbelow.

As part of the user authentication process, the authentication server110 may provide certain user profile information to the affiliateserver, such as the user's email address, user preferences, and the typeof Internet browser installed on client computer 100. This user profileinformation is associated with the user's login ID so that each time theuser logs into an affiliate server, the associated user profileinformation is available to provide to the affiliate server. This userprofile allows the user to enter the information once and use thatinformation during subsequent logins to new affiliate servers.

The term “affiliate server” is defined herein as a web server that has“registered” or otherwise established a relationship or affiliation withthe authentication server 110. Each affiliate server 104, 106, and 108includes a code sequence (not shown) that allows the affiliate server tocommunicate with the authentication server 110 when a user (who is alsoregistered with the authentication server) requests access to theaffiliate server. Additional details regarding the authenticationprocess and the interaction between the client computer, the affiliateservers, and the authentication server are provided below.

FIG. 2 shows a general example of a computer 130 that can be used withthe present invention. A computer such as that shown in FIG. 2 can beused for client computer system 100, authentication server 110, or anyof the affiliate servers 104, 106 or 108.

Computer 130 includes one or more processors or processing units 132, asystem memory 134, and a bus 136 that couples various system componentsincluding the system memory 134 to processors 132. The bus 136represents one or more of any of several types of bus structures,including a memory bus or memory controller, a peripheral bus, anaccelerated graphics port, and a processor or local bus using any of avariety of bus architectures. The system memory 134 includes read onlymemory (ROM) 138 and random access memory (RAM) 140. A basicinput/output system (BIOS) 142, containing the basic routines that helpto transfer information between elements within computer 130, such asduring start-up, is stored in ROM 138.

Computer 130 further includes a hard disk drive 144 for reading from andwriting to a hard disk (not shown), a magnetic disk drive 146 forreading from and writing to a removable magnetic disk 148, and anoptical disk drive 150 for reading from or writing to a removableoptical disk 152 such as a CD ROM or other optical media. The hard diskdrive 144, magnetic disk drive 146, and optical disk drive 150 areconnected to the bus 136 by an SCSI interface 154 or some otherappropriate interface. The drives and their associated computer-readablemedia provide nonvolatile storage of computer-readable instructions,data structures, program modules and other data for computer 130.Although the exemplary environment described herein employs a hard disk,a removable magnetic disk 148 and a removable optical disk 152, itshould be appreciated by those skilled in the art that other types ofcomputer-readable media which can store data that is accessible by acomputer, such as magnetic cassettes, flash memory cards, digital videodisks, random access memories (RAMs), read only memories (ROMs), and thelike, may also be used in the exemplary operating environment.

A number of program modules may be stored on the hard disk 144, magneticdisk 148, optical disk 152, ROM 138, or RAM 140, including an operatingsystem 158, one or more application programs 160, other program modules162, and program data 164. A user may enter commands and informationinto computer 130 through input devices such as a keyboard 166 and apointing device 168. Other input devices (not shown) may include amicrophone, joystick, game pad, satellite dish, scanner, or the like.These and other input devices are connected to the processing unit 132through an interface 170 that is coupled to the bus 136. A monitor 172or other type of display device is also connected to the bus 136 via aninterface, such as a video adapter 174. In addition to the monitor,personal computers typically include other peripheral output devices(not shown) such as speakers and printers.

Computer 130 commonly operates in a networked environment using logicalconnections to one or more remote computers, such as a remote computer176. The remote computer 176 may be another personal computer, a server,a router, a network PC, a peer device or other common network node, andtypically includes many or all of the elements described above relativeto computer 130, although only a memory storage device 178 has beenillustrated in FIG. 2. The logical connections depicted in FIG. 2include a local area network (LAN) 180 and a wide area network (WAN)182. Such networking environments are commonplace in offices,enterprise-wide computer networks, intranets, and the Internet.

When used in a LAN networking environment, computer 130 is connected tothe local network 180 through a network interface or adapter 184. Whenused in a WAN networking environment, computer 130 typically includes amodem 186 or other means for establishing communications over the widearea network 182, such as the Internet. The modem 186, which may beinternal or external, is connected to the bus 136 via a serial portinterface 156. In a networked environment, program modules depictedrelative to the personal computer 130, or portions thereof, may bestored in the remote memory storage device. It will be appreciated thatthe network connections shown are exemplary and other means ofestablishing a communications link between the computers may be used.

Generally, the data processors of computer 130 are programmed by meansof instructions stored at different times in the variouscomputer-readable storage media of the computer. Programs and operatingsystems are typically distributed, for example, on floppy disks orCD-ROMs. From there, they are installed or loaded into the secondarymemory of a computer. At execution, they are loaded at least partiallyinto the computer's primary electronic memory. The invention describedherein includes these and other various types of computer-readablestorage media when such media contain instructions or programs forimplementing the steps described below in conjunction with amicroprocessor or other data processor. The invention also includes thecomputer itself when programmed according to the methods and techniquesdescribed below.

For purposes of illustration, programs and other executable programcomponents such as the operating system are illustrated herein asdiscrete blocks, although it is recognized that such programs andcomponents reside at various times in different storage components ofthe computer, and are executed by the data processor(s) of the computer.

Prior to executing the authentication process described below, both theuser of client computer system 100 and the operator of affiliate server104 “register” with the authentication server 110. This registration isa one-time process which provides necessary information to theauthentication server. The user of client computer system 100 registersby providing the user's name, mailing address, email address, andvarious other information about the user or the client computer system.As part of the user registration process, the user is assigned (orselects) a login ID, which is a common login ID used to access anyaffiliate server. The login ID may also be referred to herein as a “username” or “login name”. Additionally, the user selects a passwordassociated with the login ID which is used for authentication purposes.After registering and logging into the authentication server, the usercan visit any affiliate server (i.e., affiliate servers that are alsoregistered with the same authentication server) without requiring anyadditional authentication and without re-entering user information thatis already contained in the associated user profile.

The operator of affiliate server 104 registers with the authenticationserver 110 by providing information about the affiliate server (e.g.,server name and internet address). Additionally, the affiliate serverprovides information regarding its authentication requirements. Theauthentication requirements can be specified as the maximum time allowedsince the last login and entry of authentication information by the useras well as the maximum time allowed since the last “refresh” of theauthentication information by the user. Refreshing the authenticationinformation refers to the process of having the user re-enter thepassword to be certain that the appropriate user is still operating theclient computer system. This periodic refreshing of authenticationinformation is useful if the user leaves their computer system withoutlogging out of the authentication server, thereby allowing anotherindividual to access affiliate servers using the login ID of theprevious user. If a user requests access to the affiliate server afterthe maximum time allowed, then the user is re-authenticated (i.e.,refreshed) by the authentication server by issuing a new authenticationticket. Thus, although there is a central authentication server, eachindividual affiliate server can establish its own authenticationrequirements which are enforced by the authentication server. Afterregistering with the authentication server, the affiliate server can usethe authentication server to authenticate any user that has alsoregistered with the authentication server.

FIGS. 3 and 4 illustrate the interaction between the client computersystem 100, the affiliate server 104, and the authentication server 110when a user of the client computer system seeks access to the affiliateserver. The example illustrated with respect to FIGS. 3 and 4 describesthe situation in which the user of the client computer system 100 hasnot yet logged into the affiliate server 104 and has not yet beenauthenticated by the authentication server 110. The lines in FIG. 3labeled “A” through “H” represent the flow of information or activitiesduring the authentication process. The arrows on the lines indicate thedirection of the process flow. The label “A” represents the beginning ofthe process and the label “H” represents the end of the process. Thecorresponding steps in FIG. 4 are indicated with the label inparenthesis.

FIG. 4 is a flow diagram illustrating the authentication process when auser of the client computer system 100 seeks access to the affiliateserver 104. The process begins when the user of the client computersystem accesses a web page on the affiliate server (step 200). Theclient computer system includes a web browser, such as the “InternetExplorer” web browser manufactured and distributed by MicrosoftCorporation of Redmond, Wash., for accessing various web sites. Theaffiliate server determines whether the user seeking access to theserver is already logged into the affiliate server (e.g., authenticated)at step 202. In this example, the user is not logged into the affiliateserver, so the user must be authenticated before the affiliate serverwill allow access. To authenticate the user, the affiliate serverredirects the user's browser to the authentication server.

In this example, the user has not yet logged into the authenticationserver. Thus, the authentication server generates a sign-in web page andcommunicates the web page to the client computer system for display onthe user's browser (step 204). The sign-in web page requests the user'slogin ID and password, which were established when the user registeredwith the authentication server. The user fills-in the requestedinformation on the sign-in web page and clicks a “sign-in” button on theweb page to send the information entered to the authentication server(step 206).

Upon receiving the information from the user of the client computersystem, the authentication server compares the entered information withthe information stored in the authentication database (step 208). If theuser-entered information is not correct (i.e., does not match theinformation stored in the authentication database) then theauthentication server generates and communicates a web page to the userindicating the login ID and password combination were not valid (step210). The web page may give the user an opportunity to re-enter thelogin ID and password by returning to step 204. Confidential information(such as the login ID and password) is communicated using a secureprotocol such as SSL (secure sockets layer). Various other secureprotocols or encryption mechanisms can be used to communicateconfidential information between the authentication server and theclient computer system.

If the user-entered information is correct (i.e., matches theinformation stored in the authentication database) then theauthentication server copies the appropriate cookies to the clientcomputer system and redirects the user's browser to the affiliate server(step 212). A “cookie” is a piece of data provided to a web browser by aweb server. The data (i.e., cookie) is sent back to the web server bythe web browser during subsequent accesses to the web server. Withrespect to step 212, one cookie contains information regarding the dateand time that the user was authenticated by the authentication server.Another cookie contains information regarding the user profile. Theauthentication server also updates (or creates) a cookie that contains alist of all sites (or web servers) visited by the user since the lastlogout from the authentication server. The cookie is updated by addingthe current affiliate server to the list of sites visited. This list ofsites visited is used to remove cookies from the client computer systemwhen the user logs out of the authentication server. For example, whenthe user logs out, the authentication server sends a message to each webserver on the list of sites visited. Each message is a request for theweb server to delete any cookies it placed on the client computer system(e.g., through a browser running on the client computer system).

Cookies written to the client computer system by the authenticationserver cannot be read by any affiliate server. Similarly, cookieswritten to the client computer system by a particular affiliate servercannot be read by any other affiliate server. The cookies written by anaffiliate server are encrypted using a key that is unique to theaffiliate server, thereby preventing other affiliate servers fromreading the data stored in the cookies.

Step 212 also includes generating an authentication ticket andtransmitting the ticket to the affiliate server. The authenticationticket is generated by the authentication server and indicates whether aparticular user has been authenticated by the authentication server. Toprotect the user's password and other login information, the affiliateserver receives the authentication ticket instead of the user's passwordand other login information. The authentication ticket indicates thatthe user is authenticated and how much time has elapsed since the userwas last authenticated.

The authentication server also communicates the user profile informationto the affiliate server (step 214) through the client computer system.In a particular embodiment of the invention, the user of the clientcomputer system can specify during the registration process what typesof profile information should be provided to various types of webservers. For example, a user may specify that all commerce-related webservers should receive the user's mailing address, but restrict themailing address from all other types of web sites.

After receiving the authentication ticket and the user's profileinformation, the affiliate server generates a personalized web page forthe user and communicates the web page to the user's browser (step 216).Additionally, the affiliate server copies one or more cookies to theclient computer system which include information indicating that theuser of the client computer system has been authenticated and indicatingthe period of time during which the authentication is valid. Each timethe user enters a new web page request on the same affiliate server, thedata in the cookie is copied to the affiliate server along with the pagerequest. Thus, the affiliate server will not repeatedly check theauthentication of a user during each subsequent page request. However,if a particular period of time has passed (referred to as a timeoutperiod) since the last authentication process by the authenticationserver, then the affiliate server may request a re-authorization of theuser.

The authentication ticket discussed above contains two time stamps. Thefirst time stamp indicates the last time that the user's login ID andpassword were physically typed by the user. The second time stampindicates the last time that the user's login information was refreshedby the authentication server. This “refresh” of the user's logininformation can be performed “silently” or by manual entry of the logininformation (i.e., login ID and password) by the user. The refreshing ofthe user's login information is performed by the authentication server.Once completed, a new authentication ticket is issued to the affiliateserver indicating the new time stamp values. If the refresh operationfails (i.e., the user does not supply the correct login information),then the user is logged out of the authentication server and allaffiliate servers.

Each affiliate server can specify the minimum time requirements for eachtime stamp in the authentication ticket. If either time stamp exceedsthe minimum time requirement for the affiliate server, then theauthentication server is contacted to re-authenticate (or refresh) theuser login information and update the time stamps accordingly. Eachauthentication ticket is encrypted using the affiliate server's sharedencryption key, thereby preventing other affiliate servers from viewingthe authentication ticket.

If the user of the client computer system is new to the affiliateserver, the affiliate server may request additional user informationthat is not already contained in the user profile. The additionalinformation may include information unique to that site (e.g., accountnumber) or information about the user's preferences and how the userintends to use the web site. Thus, although the user generates a userprofile that is stored on the authentication server, the user may berequired, during an initial visit to a web site, to provide additionalinformation for the benefit of the associated web server. Thisadditional information is then stored by the affiliate server such thatthe user will not be required to re-enter the data during subsequentvisits to the same web site.

Although affiliate server 104 and authentication server 110 are bothcoupled to network 102 (see FIG. 1), no direct connections are shown inFIG. 3. In this embodiment of the invention, the affiliate server 104and the authentication server 110 do not communicate directly with oneanother. Instead, communications between the affiliate server and theauthentication server pass through the client computer system. However,in an alternate embodiment of the invention, affiliate server 104communicates directly with authentication server 110, using network 102or another data communication medium. Thus, rather than communicatingthrough client computer system 100, the communications flow directlybetween the authentication server and the affiliate server. Although theauthentication server and the affiliate server communicate directly, theuser's authentication information (e.g., password) is not exposed to theaffiliate server.

After a user has logged into the authentication server, it is notnecessary to re-enter the login ID, password, or other user informationwhen accessing other affiliated web servers. The subsequent affiliateweb servers accessed will determine from the authentication server thatthe user is already authenticated.

FIGS. 5 and 6 illustrate the interaction between the client computersystem, a particular affiliate server and the authentication server in adifferent situation. The example illustrated with respect to FIGS. 5 and6 describes the situation in which the client computer system 100 hasalready been authenticated by the authentication server 110 (e.g., whenlogging into a different affiliate server), but the client computersystem is not yet logged into the affiliate server 104.

In this example, the user of the client computer system 100 accesses aweb page on the affiliate server 104 (step 230). The affiliate serverdetermines that the user is not authenticated (with respect to theaffiliate server) and redirects the user's browser to the authenticationserver (step 232). Next, the authentication server retrieves theaffiliate information entered during registration of the affiliate todetermine whether the most recent authentication of the user is withinthe affiliate's timeout period (step 234). If the most recentauthentication is not within the timeout period (i.e., not acceptable),then the authentication server retrieves and authenticates the user'slogin ID and password (step 238) using, for example, the proceduresdiscussed above with respect to FIG. 4.

If the most recent authentication is acceptable, then the authenticationserver copies the appropriate cookies to the client computer system andredirects the user's browser back to the affiliate server (step 240).Additionally, the authentication server generates an authenticationticket, which is communicated to the affiliate server. As discussedabove, the authentication ticket indicates to the affiliate server thatthe user is authenticated. Furthermore, the authentication ticketincludes two timestamps indicating the elapsed time since the last userauthentication.

The authentication server also copies certain elements of the user'sprofile information to the affiliate server (step 242). The affiliateserver then generates a personalized web page and communicates the webpage to the user's browser (step 244). The affiliate server also copiesa cookie to the client computer system containing information indicatingthat the user of the client computer system has been authenticated andindicating the period of time during which the authentication is valid.Each time the user enters a new web page request on the same affiliateserver, the data in the cookie is copied to the affiliate server alongwith the page request. Thus, the affiliate server will not repeatedlycheck the authentication of a user during each subsequent page request.

In an embodiment of the invention, a particular affiliate server mayutilize only a portion of the services available from the authenticationserver. For example, the affiliate server may perform its ownauthentication of the user, but requests the user profile informationfrom the authentication server. In another example, the affiliate servermay rely on the authentication server to authenticate the user, but theaffiliate server ignores the user profile information and, instead,collects information from the user itself

In one embodiment of the invention, the same login ID is used toidentify a particular user on all affiliate servers. However, thisconfiguration presents a situation in which affiliate servers couldexchange information collected about the user with other affiliateservers, relying on the common login ID. To avoid this situation, asecond embodiment of the invention uses a different login ID for each ofthe affiliate servers. This use of different login IDs is transparent tothe user, who only knows of the login ID used to log into theauthentication server. The authorization server maintains a list orcross-reference table that correlates the user's login ID on thedifferent affiliate servers. In this embodiment, the affiliate serversdo not know the login ID used on other affiliate servers for the sameuser and, therefore, cannot exchange information about the user withother affiliate servers.

A particular embodiment of the invention has been described andillustrated herein with reference to multiple web servers and anauthentication server coupled to a common data communication network.However, the teachings of the present invention can be applied to anytype of web server or other computing device that accesses a centralizedauthentication system to authenticate a user and retrieve associateduser profile information. Furthermore, the present invention can beutilized without requiring a data communication network. Instead, one ormore temporary or permanent data communication links are establishedbetween an authentication server and an affiliate server for exchangingdata.

Thus, a system has been described that allows a web server toauthenticate a user seeking access to the web server. The authenticationis performed by an authentication server without exposing the user'sauthentication information (e.g., password) to the web server. The webserver receives an authentication ticket from the authentication serverindicating whether the authentication was successful and furtherindicating the time since the last user authentication. Theauthentication server may also provide user profile information to theweb server if the user is authenticated. Thus, the authentication serverprovides a centralized device for authenticating users without exposingthe user's confidential login information to an affiliate server. Thissingle user profile may be provided to multiple affiliate serverswithout requiring repeated entry of information by the user (i.e.,entering user information at each new web site visited). Once the userhas been authenticated by the authentication server, the user can visitmultiple web sites that are affiliated with the authentication serverwithout re-entering the authentication information for each web site.

Although the invention has been described in language specific tostructural features and/or methodological steps, it is to be understoodthat the invention defined in the appended claims is not necessarilylimited to the specific features or steps described. Rather, thespecific features and steps are disclosed as preferred forms ofimplementing the claimed invention.

What is claimed is:
 1. A method of accessing a web server coupled to the Internet, the method comprising: receiving a request from a web server to authenticate a user of an Internet browser seeking access to the web server; determining whether the user was already authenticated by an authentication server; if the user was already authenticated by the authentication server, generating an authentication ticket and communicating the authentication ticket to the web server; if the user was not already authenticated by the authentication server, then communicating a web from the authentication server to an Internet browser operated by the user, wherein the web page requests login information to be returned to the authentication server from the user; receiving the completed web page at the authentication server from the user; authenticating the user by comparing the information received in the completed web page with authentication information maintained by the authentication server; and if the information received in the completed web page matches the authentication information, generating an authentication ticket at the authentication server and communicating the authentication ticket from the authentication server to the web server.
 2. A method as recited in claim 1 wherein the authentication ticket includes an indication that the user is authenticated.
 3. A method as recited in claim 1 wherein the authentication ticket does not contain any reference to the user's login information.
 4. A method as recited in claim 1 wherein the authentication ticket does not contain any reference to the information received in the completed web page.
 5. A method as recited in claim 1 wherein the authentication ticket includes a first time stamp indicating the last time the user's login information was refreshed.
 6. A method as recited in claim 1 wherein the authentication ticket includes a second time stamp indicating the last time the user physically entered their login information.
 7. A method as recited in claim 1 wherein the authentication ticket includes: a first time stamp indicating the last time the user's login information was refreshed; and includes a second time stamp indicating the last time the user physically entered their login information.
 8. The method of claim 1, wherein the login information is used to authenticate the user with respect to the authentication server but is not used to directly authenticate the user with respect to the web server.
 9. One or more computer-readable memories containing a computer program that is executable by a processor to perform the method recited in claim
 1. 10. A method of authenticating a user, the method comprising: receiving, at an authentication server, a request to authenticate a user, wherein the request is generated by a network server to which the user is seeking access; determining whether the user was already authenticated by the authentication server; if the user was already authenticated by the authentication server, generating an authentication ticket and communicating the authentication ticket to the network server, wherein the authentication ticket includes an indication that the user is authenticated; and if the user was not already authenticated by the authentication server, then retrieving login information by the authentication server from the user, authenticating the user at the authentication server by comparing the retrieved login information with authentication information maintained by the authentication server, and if the retrieved login information matches the authentication information, generating an authentication ticket at the authentication server and communicating the authentication ticket from the authentication server to the network server, wherein the authentication ticket includes an indication that the user is authenticated.
 11. A method as recited in claim 10 wherein the authentication ticket further includes: a first time stamp indicating the last time the user's login information was refreshed; and a second time stamp indicating the last time the user physically entered their login information.
 12. A method as recited in claim 10 wherein the network server is a web server coupled to the Internet.
 13. A method as recited in claim 10 wherein the method is performed by the authentication server, which is coupled to the Internet.
 14. A method as recited in claim 10 wherein the retrieved login information includes a login ID and a password associated with the login ID.
 15. A method as recited in claim 10 further comprising concealing the retrieved login information from the network server.
 16. A method as recited in claim 10 further comprising concealing the authentication information maintained by the authentication server from the network server.
 17. A method as recited in claim 10 wherein the user previously registered with the authentication server.
 18. A method as recited in claim 10 wherein the network server previously registered with the authentication server.
 19. The method of claim 10, wherein the login information is used to authenticate the user with respect to the authentication server but is not used to directly authenticate the user with respect to the network server.
 20. One or more computer-readable memories containing a computer program that is executable by a processor to perform the method recited in claim
 10. 21. One or more computer-readable media having stored hereon a computer program comprising the following steps: receiving a request to authenticate a user seeking access to a network server; determining whether the user was already authenticated by an authentication server; if the user was already authenticated by the authentication server, generating an authentication ticket and communicating the authentication ticket to the network server; and if the user was not already authenticated by the authentication server, then retrieving login information by the authentication server from the user, authenticating the user at the authentication server by comparing the retrieved login information with authentication information maintained by the authentication server, if the retrieved login information matches the authentication information, generating an authentication ticket at the authentication server and communicating the authentication ticket from the authentication server to the network server.
 22. One or more computer-readable media as recited in claim 21 wherein the authentication ticket includes an indication of whether the user is authenticated.
 23. One or more computer-readable media as recited in claim 21 wherein the authentication ticket does not contain any reference to the retrieved login information.
 24. One or more computer-readable media as recited in claim 21 wherein the authentication ticket does not contain any reference to the user's login information.
 25. One or more computer-readable media as recited in claim 21 wherein the authentication ticket includes a first time stamp indicating the last time the user's login information was refreshed.
 26. One or more computer-readable media as recited in claim 21 wherein the authentication ticket includes a second time stamp indicating the last time the user physically entered their login information.
 27. The computer program of claim 21, wherein the login information is used to authenticate the user with respect to the authentication server but is not used to directly authenticate the user with respect to the network server.
 28. A method of granting access to a network server, the method comprising: receiving a request by a user to gain access to the network server; generating a request to authenticate the user, from the authentication server the request includes the user's login information; communicating the request to an authentication server; receiving an authentication ticket at the network server from the authentication server indicating whether the user is authenticated; granting access to the user at the network server if the authentication ticket indicates that the user is authenticated at the authentication server; and denying access to the user if the authentication ticket indicates that the user is not authenticated.
 29. A method as recited in claim 28 wherein the authentication ticket further includes a first time stamp indicating the last time the user's login information was refreshed.
 30. A method as recited in claim 28 wherein the authentication ticket further includes a second time stamp indicating the last time the user physically entered their login information.
 31. The method of claim 28, wherein the login information is used to authenticate the user with respect to the authentication server but is not used to directly authenticate the user with respect to the network server.
 32. One or more computer-readable memories containing a computer program that is executable by a processor to perform the method recited in claim
 28. 33. One or more computer-readable media having stored thereon a computer program comprising the following steps: receiving a request by a user to gain access to a network server; generating a request to authenticate the user from an authentication server to be returned to the authentication server; communicating the request, includes the user's login information to the authentication server; receiving an authentication ticket at the network server from the authentication server indicating whether the user is authenticated; granting access to the user, at the network server if the authentication ticket indicates that the user is authenticated; and denying access to the user, at the network server if the authentication ticket indicates that the user is not authenticated.
 34. One or more computer-readable media as recited in claim 33 wherein the authentication ticket includes a first time stamp indicating the last time the user's login information was refreshed.
 35. One or more computer-readable media as recited in claim 33 wherein the authentication ticket includes a second time stamp indicating the last time the user physically entered their login information.
 36. The computer program of claim 33, wherein the login information is used to authenticate the user with respect to the authentication server but is not used to directly authenticate the user with respect to the network server. 